Regulating zinc deposition with fluorinated polyimide/cellulose composite nanofiber separators for dendrite-free zinc-ion batteries

Currently, the advancement of aqueous zinc-ion batteries (ZIBs) is extensively hampered by challenges such as formation of zinc dendrites and side reactions on the zinc anode. As a crucial element of batteries, the separator can greatly affect battery performance, and the present study aims to develop a novel separator to tackle the above challenges in aqueous ZIBs. Toward this end, a nonwoven fabric of fluorinated polyimide/cellulose (fPC) composite nanofiber is succesfully manufactured through electrospinning. The resultant membrane exhibits a uniform pore structure, abundant zincophilic groups, high hydrophilicity and excellent mechanical properties. When used as a separator for aqueous ZIBs, the fPC membrane can effectively promote zinc ion transport and achieve uniform Zn 2+ deposition, effectively and concurrently suppressing both dendrite formation and side reactions. As a consequence, the aqueous Zn||Zn symmetric cell assembled with fPC exhibits superior cycle stability over 1800 h at 1 mA cm −2 /1 mAh cm −2 , while the aqueous Zn||MnO 2 full cell displays excellent rate performance and stable cycling performance, suggesting the high potential of fPC in real-world aqueous ZIB applications.